Liu Delei, Liu Jianghao, Ye Peikan, Zhang Haijun, Zhang Shaowei
The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China.
College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, UK.
Materials (Basel). 2022 Apr 11;15(8):2799. doi: 10.3390/ma15082799.
Urchin-like tantalum diboride (TaB2) nanoflowers were successfully synthesized via a high-efficiency and energy-saving methodology, molten-salt and microwave co-modified boro/carbothermal reduction, using less expensive B4C as a reducing agent. By taking advantage of the synergistic effects of the molten-salt medium and microwave heating conditions, the onset formation temperature of TaB2 was drastically reduced to below 1000 °C, and phase-pure powders of TaB2 nanoflowers were obtained at temperatures as low as 1200 °C within only 20 min. Notably, the present temperature conditions were remarkably milder than those (>1500 °C for several hours) required by conventional reduction methods, which use the strong, but expensive, reducing agent, elemental boron. The resulting urchin-like TaB2 nanoflowers consisted of numerous uniform single-crystalline nanowires with lengths up to 4.16 μm, and high aspect ratios >10. This result indicated that the as-synthesized urchin-like TaB2 nanoflowers possessed high specific surface area and anisotropic morphology, which were favorable not only for sintering, but also for toughening their bulk counterparts.
通过一种高效节能的方法，即熔盐与微波共改性硼/碳热还原法，以价格较低的B4C作为还原剂，成功合成了海胆状二硼化钽（TaB2）纳米花。利用熔盐介质和微波加热条件的协同效应，TaB2的起始形成温度大幅降至1000℃以下，并且仅在20分钟内，就能在低至1200℃的温度下获得纯相的TaB2纳米花粉末。值得注意的是，当前的温度条件明显比传统还原方法所需的条件（>1500℃，数小时）温和得多，传统方法使用的是强还原剂但价格昂贵的元素硼。所得到的海胆状TaB2纳米花由许多长度高达4.16μm、长径比>10的均匀单晶纳米线组成。这一结果表明，所合成的海胆状TaB2纳米花具有高比表面积和各向异性形态，这不仅有利于烧结，也有利于增强其块状材料。
